1. Field of the Invention
The invention relates to a method and apparatus for receiving and transmitting data in a network, and more particularly, to a method for receiving and transmitting data between separate Fibre Channel fabrics.
2. Description of the Related Art
As computing power has increased over the years, the need for high performance storage capacity has also increased. To this end, storage area networks (SANs) have been developed. Basically a SAN is an interconnection network between a series of hosts or servers and a series of storage devices. The interconnection network is very high performance to allow each of the servers to access each of the desired storage units without significant performance penalties. The use of SANs allows a more optimal use of the available storage capacity than would otherwise be the case if the storage capacity was directly attached to the particular hosts.
The preferred interconnection network for SANs is Fibre Channel. This is a high speed link system according to a series of ANSI standards. In a Fibre Channel network a series of fabrics or inter-switch connections are developed. Hosts are connected to the fabric, as are the storage units. Then the interconnected switches in the fabric provide a path or route between the host and the storage unit. Thus the development of SANs has allowed very large increases in cost effective storage capacity.
However, there are certain problems when developing networks using Fibre Channel switches. One of the problems is that there can only be 239 distinct domains in a Fibre Channel fabric. Further, there are many conditions under which the fabric will segment or break into two fabrics, so that communication between devices on the two fabrics is not possible. For example, segmentation can be caused when certain parameters associated with the particular switches are not set to the proper values. As the number of switches in the fabric grows larger, the chances of segmentation ever increase. In fact, in many cases it is not possible to maintain all of the desired switches in a single fabric. This then hinders configuration of the particular network because certain devices will not be allowed to access other devices because the two fabrics are not connected. Therefore, it is desirable to have a way to connect the two fabrics so that devices can talk across the two fabrics without requiring that the fabrics be merged or allowing the combination of the two fabrics to have a total of more than 239 domains.